From b608b283a962caaa280756bc8563016a71712acf Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Fri, 30 Jul 2010 15:31:54 -0400 Subject: [PATCH] NFS: kswapd must not block in nfs_release_page See https://bugzilla.kernel.org/show_bug.cgi?id=16056 If other processes are blocked waiting for kswapd to free up some memory so that they can make progress, then we cannot allow kswapd to block on those processes. Signed-off-by: Trond Myklebust Cc: stable@kernel.org --- fs/nfs/file.c | 13 +++++++++++-- fs/nfs/write.c | 4 ++-- include/linux/nfs_fs.h | 1 + 3 files changed, 14 insertions(+), 4 deletions(-) diff --git a/fs/nfs/file.c b/fs/nfs/file.c index 36a5e74f51b..f036153d9f5 100644 --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #include @@ -493,11 +494,19 @@ static void nfs_invalidate_page(struct page *page, unsigned long offset) */ static int nfs_release_page(struct page *page, gfp_t gfp) { + struct address_space *mapping = page->mapping; + dfprintk(PAGECACHE, "NFS: release_page(%p)\n", page); /* Only do I/O if gfp is a superset of GFP_KERNEL */ - if ((gfp & GFP_KERNEL) == GFP_KERNEL) - nfs_wb_page(page->mapping->host, page); + if (mapping && (gfp & GFP_KERNEL) == GFP_KERNEL) { + int how = FLUSH_SYNC; + + /* Don't let kswapd deadlock waiting for OOM RPC calls */ + if (current_is_kswapd()) + how = 0; + nfs_commit_inode(mapping->host, how); + } /* If PagePrivate() is set, then the page is not freeable */ if (PagePrivate(page)) return 0; diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 91679e2631e..0a6c65a1f9d 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -1379,7 +1379,7 @@ static const struct rpc_call_ops nfs_commit_ops = { .rpc_release = nfs_commit_release, }; -static int nfs_commit_inode(struct inode *inode, int how) +int nfs_commit_inode(struct inode *inode, int how) { LIST_HEAD(head); int may_wait = how & FLUSH_SYNC; @@ -1443,7 +1443,7 @@ out_mark_dirty: return ret; } #else -static int nfs_commit_inode(struct inode *inode, int how) +int nfs_commit_inode(struct inode *inode, int how) { return 0; } diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h index 77c2ae53431..f6e2455f13d 100644 --- a/include/linux/nfs_fs.h +++ b/include/linux/nfs_fs.h @@ -493,6 +493,7 @@ extern int nfs_wb_all(struct inode *inode); extern int nfs_wb_page(struct inode *inode, struct page* page); extern int nfs_wb_page_cancel(struct inode *inode, struct page* page); #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4) +extern int nfs_commit_inode(struct inode *, int); extern struct nfs_write_data *nfs_commitdata_alloc(void); extern void nfs_commit_free(struct nfs_write_data *wdata); #endif -- 2.34.1